Signaling apparatus



Patented 7 July 15, 1930 UNITED STATES LTMSZZ JAMES J. VANHORN, 0FPITTSBURGH, PENNSYLVANIA,- ASSIGNOR TO THE UNION SWITCH & SIGNALCOMPANY, OF SVVIIISSVJLLE, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIASIGNALING APPARATUS Applicationfiled October 20, 1928. Serial No.313,751;

My invention relates to signaling apparatus, and particularly toapparatus for indicating at one point, the condition of a plurality ofdevices located at another point by means of a single pairof line wiresextending between such points.

I willdescribe two formsof apparatus embodying my invention, and willthen point out the novel features thereof in claims.

In the accompanying drawing, Fig. 1 is a diagrammatic view illustratingone form of signaling apparatus embodying my invention. Fig. 2 is asimilar View showing a modified form of the apparatus illustrated inFig. 1, and also embodying my invention.

Similar reference characters refer to similar parts in both views.

Referring first to Fig. 1, the reference character A designates asection of railway track which is insulated from the adjacent trackby'means of insulated joints 90, and the reference character Bdesignates a similar section, here shown as part of a parallel track.Section A is provided with a track circuit comprising a track relay Rconnected across the rails adjacent one end of the section and a trackbattery C connected across the rails adjacent the other end of thesection Section B isprovided with a similar track circuit comprising atrack relay R connected across the rails ad acentone end of the section,and a track battery C connected across the rails adjacent the other endof the section.

Associated with track relays R and B is a slow acting relay S which isarranged to be energized only when these track relays are bothenergized. The pick-up circuit for relay S passes from a suitable sourcesuch as a battery H, through wire 23, front contact 24 of track relay Rwire 25, front contact 26 of track relay R wire 27, winding of relay S,and wire 28 b ack to battery H. Relay S is, therefore, de-energizedwhena train occupies either section A or section B.

, Located at a remote point, such for example as a train despat'chersofiice, are a neutral relay T, and a polarized relay P. These relays areconstructed in such manner that a larger current is required to operaterelay '1 than is required to operate relay P. As here shown, relay P isof the usual polarized direct current type, and comprises two neutralcontacts 32 and 39, and a polar contact 3%, which may be movedintoeither a righthand or normal position, as shown in the drawing, or intoa left-hand or reverse position, depending upon the'polarity of the cur-A rent suppliedto the relay. Direct current polarized relays of the'typedescribed are customarily arranged so that when the relay.

is ole-energized the polar contact remains in the position to which it.was last moved.

The relays T and P control indicators here shown-as two electric lamps Land L which inform the dcspatcher concerning the condition of tracksections A and B.

As shown in the drawing, sections A and B are both unoccupiedflrackrelays It and R are both energized, and slow acting relay S isenergized. A first circuit for relays T and P is then closed, andcurrent flows from two batteries E- and F in series through wire 1,front contact 2 of track relay R wire 3, frontcontact 4 of track relay Rwires 5 and 6, winding of relay P, wire 7, winding of relay T, and wires8 and 9v back to batteries E and Fin series. The magnitude of thecurentwhich flows in this first circuit is sufficient to operate bothrelays T andP, and the polarity ofthis current is what I shall termnormal polarity, so that, under these conditions, relays T and P areboth energized, and contact 34 of relay P occupies its normal position.WVhen relays T and P are both energized, lampsfll and L are both dark,thereby informing the despatcher that track sections A and B are bothunoccupied.

I will now assume that section B remains unoccupied, but that a trainenters section A, thereby tie-energizing track relay R The first circuitfor relays T and P is then opened at front contact 1 of track relay Rand at the same time, the circuit for relay S is opened at front contact26 of track relay R Due, however, to the slow-acting characteristics ofrelay S, an interval of time elapses after the opening of relay R andprior to the opening of relay S. During this time interval relays T andP are both deenergized, and this time interval is long to insure thatboth these relays open. When back contact 16 of relay S closes, at theexpiration of its holding interval, a second cir cuit for relays Tand Pis closed, and current then flows from battery F through wire 11, frontcontact 12 of track relay R wire 13, back contact 14 of track relay Rwire 15, back contact 16 of slow-acting relay S, wires 17 and 6, windingof relay P, wire 7 winding of relay T, and wires 3 and 9 back to batteryF. The current which flows in this second circuit for relays T and P isof the same polarity as, but is less in magnitude than the current whichflows in the circuit first traced for these relays, and is sufficient tooperate relay P, but is not sufficient to operate relay T. It followsthat when this second circuit is closed relay T is open, but relay P isclosed in the normal direction. A circuit for lamp L is then closed, andcur rent flows from a suitable source, such as a battery J, through wire29, back contact 30 of relay T, wire 31, front contact 32 of relay P,wire 33, normal contact 3d of relay P, wire 37, lamp L and wires 38 and36 back to battery J. Under these conditions, therefore, lamp L islighted, indicating that section A is occupied by a train.

I will next assume that both sections A and B are unoccupied, and that atrain enters section B. Relay R therefore becomes deenergized, and whenthis relay opens, the circuit first traced for relays T and P is openedat front contact 2 of relay R and at the same time, the circuit forrelay S is opened at front contact 24: of relay R As was previouslyexplained relay S does not open until the expiration of a time intervalwhich is long enough to permit both relays T and P to open. When backcontact 16 of relay S finally closes, a third circuit for relays T and Pis closed, and current flows from a battery G through wires 22 and 8,winding of relay T, wire 7, winding of relay P, wires 6 and 17, backcontact 16 of slow-acting relay S, wire 15, front contact 18 of trackrelay R wire 19, back contact 20 of track relay R and wire 21 back tobattery G. The current which flows in this third circuit for relays Tand P has the same magnitude as the current which flows in the secondcircuit for 'these relays but is of the opposite or reverse polarity, sothat relay T is open and relay P is closed in the reverse direction. Acircuit for lamp L is then completed from battery J, through wire 29,back contact of relay T, wire 31, front contact 32 of relay P, wire 33,reverse contact 3A of relay T, wire 35, lamp L and wire 36 back tobattery J. Lamp L is, therefore, lighted to indicate that section B isoccupied by a train.

Finally, I will assume that trains occupy both sections A and 13. Trackrelays R and R are, therefore, both tie-energized, and all threecircuits for relays T and P are then open, so that relays T and P areboth open. Under these conditions, circuits for lamps L and L are bothclosed. The circuit for lamp L passes from battery J, through wire 29,back contact 30 of relay T, wire 31, back contact 32 of relay P, wires41 and 37, lamp L and wires 38 and 36 back to battery J. The circuit forlamp L passes from battery J, through wire 29, back contact 30 of relayT, wire 31, back contact 39 of relay P, wire 40, lamp L and wire 36,back to battery J. Lamps L and L are, therefore, both lighted,indicating that track sections A and B are both occupied.

, It will be noted from the foregoing that when track sections A and Bare both unoccupied so that track relays R and R are both energized,relays T and P are supplied with current having a magnitude which issuflicient to operate both relays. It will also be noted. from theforegoing, that when a train enters either section A or section B, sothat track relay PM or R becomes de-energized, relays T and P are thensupplied with current having a magnitude which is less than themagnitude of the current supplied to these relays when sections A and Bare both unoccupied, and this current of reduced magnitude is sufficientto operate relay P but is not 'suiiicient to operate relay T. l/Vithstandard apparatus for accomplishing these results it might happen thatwhen a train entered either section A or section B to de energize trackrelay R or track relay R this current of reduced magnitude would besupplied to relays T and P before these relays had opened, and relay Tmight under some conditions be held up by this current, therebyproducing an undesirable condition. With apparatus embodying myinvention, however, this undesirable condition cannot exist. That is tosay, when a train enters either section A or section B, so that relay Bor E becomes ole-energized, the first circuit for relays T and P isopened, and these relays are completely (ls-energized until either thesecond or third circuits for these relays is closed at back contact 16of relay S. The circuit for relay S is opened at the same time as thefirst circuit for relays T and P, but due to the slow-actingcharacteristics of relay S, back contact 16 of relay S does not becomeclosed until after a time interval has elapsed, which time interval issufficiently because the magnitude of the current supplied to theserelays is sufficient to operate relay P but is not sufficient to operaterelay T.

In the modified form of apparatus shown in Fig. 2, I employ threeneutral relays U, V,

r and W, instead of the neutral relay T and the polarized relay P usedin Fig. 1. These rela s are so arran ed that the re uire rogressivelylarger currents to cause the relays to pick-up, relay VJ picking up withthe smallest value of current, and relay U with the largest value ofcurrent.

As shown in F 2, track sections A and B are both unoccupied, relays Rand R are both energized, and slow-acting relay S is i also energized.Under these conditions,cur-

rent is supplied to relays U, V, and W in series from two batteries Xand Y in series over a first circuit which passes from battery X throughwires 42 and 4.3, front contact i l of track relay R wires 45 and 45,front contact 47 of track relay R wires 48 and 49, winding of relay U,wire 50, winding of relay V, wire 51, winding of relay \V, wires 52- and58, front contact 54 of track relay R wires 55 and 56, front contact 57of track relay R and wire 58 back to battery Y. It will be noted thatbatteries X and Y are connected in series in this circuit, and themagnitude of the current supplied to relays U, V, and VV over thiscircuit is suiiicient to pickup all three of these relays. Lamps L and Lare then both dark, indicating that track sections A. and B are bothunoccupied.

T will now assume that track sections A and B are both unoccupied, andthat a train enters track section 1%. Relay R therefore becomes(ls-energized. When front contact at of this relay opens, the firstcircuit for relays U. V, and W is opened, and when front contact 24 ofthis relay opens, the circuit for this time interval is sufficientlylong to permit all three of these relays to open. l/Vhen back contact 67of relay S closes, a second circuit for relays U, V, and W is closed,and current flows from battery X through wires a2 and 82, back contact61 of track relay R wires 62 and ai, front contact 47 of track relay Rwires l8 and 49, winding. of relay U, wire 50, winding of relay V, wire51, winding of relay V, wires 52 and 63, front contact 6 oftrack relay Rwires '65 and 66, back contact 67 of relay S, and wires 68 and back tobattery X. The magnitudeof the .current which flows in this secondcircuit tude of the current which flows in the first circuit for theserelays, and is sufficient to operate relays V and W, but is notsufficient to operate relay U. When this circuit is closed, therefore,relays V and TN are picked up and relay U is open. Undertheseconditions, a circuit for lamp L is closed and current flows frombattery J through wire 7 5,

back contact 7 6 of relay U, wire 77, front con-' tact 78 of relay V,wire 88, front contact 84 of'reliy W, wires and 86, lamp L and wire 81back to battery J. Lamp L is, therefore, lighted, indicating thatsection B is occupied.

I will next assume that with sections A and B both unoccupied, a trainenters track section A. Track relay R then becomes de energized, and thefirst circuit for relays U, V, and VV is opened at front contact 47 oftrack relay R At the same time, the circuit for slow-acting relay S isopened at front contact 26 of track relay R After the expiration of atime interval relay S opens and closes its back contact. During thistime interval relays U, V, and l/V are de-energized,

and this time interval is sufficiently long to permit all three of theserelays to open.

When back contact 67- of relay S closes, a third circuit for relays U,V, and W is then closed, and current flows from a battery Y throughwires 59 and 68, back contact 6? of slow-acting relay S, wires 66 and72, front contact 73 of track relay R wires *1 and 52,

ate relays U and V, so that'when this circuitv is closed relay W ispicked up, but relays U and Vare both open. Under these conditions, acircuit for lamp L is lighted and current flows from' battery J throughwire 75, back contact 76 of relay U, wire '47, back contact 78 of relayV, wires 79 and 80, lamp L and wire 81 back to battery J. Lamp thereforebecomes lighted indicating that track section A is occupied.

Finally, I will assume that trains occupy both track sections A'an'd B,so that relays R and R are both de energized. All three circuits forrelays U, V, and VV, then opened at front contacts of track relays R andR and relays U, V, and V are all de-energized. Under these conditionscircuits for lamps L and L are both closed. The cirquit for lamp Lpasses from battery J through wire 7 5, back contact 76 of relay U,

- wire 77, back contact 78 of relay V, wires Y9 Wires 7 9 and 87, backcontact 88 of relay WV, wires 89 and 86, lamp L and wire 81 back tobattery J. Lamps L and L are then both lighted indicating that tracksections A and B are both occupied.

It will be noted that in Fig. 2, when track relays R and R are bothenergized, as when track sections A and B are both unoccupied, relays U,V, and IN, are supplied with current having a magnitude which issufi'icient ,to energize all three of these relays, but that when eithertrack relay R or track relay R is de-energized, as when a train occupiestrack section B, or track section A, relays U, V, and W are thensupplied with current having a magnitude which is sufficient to energizeonly relays V and WV, or relay W depending upon whether section B orsection A is the occupied section. VVith standard apparatus forobtaining the above results it might happen that when a train enteredeither section A or section B-to de-energize track relay B or 1 relaysU, V, and W would be supplied with current of decrease-d magnitudebefore these relays opened, and one or more of the relays U, V, or Wwhich should open under normal conditions might be held up. therebyproducing an undesirable condition. lVith apparatus embodying myinvention, however, this undesirable condition cannot exist. For, when atrain enters section A or section B to de-energize either track relay Ror R relays U, V, and W are then completely de-energized untilslow-acting relay S opens and closes its back contact 67. lPhe circuitfor slow-acting relay S is opened at the same time as the circuit overwhich current is normally supplied to relays U, V, and W when trackrelays R and R are both energized, but due to the slow-actingcharacteristics of relay S, relay S does not open and close its backcontact 67, until after a time interval 'has elapsed which issufficiently long to permit relays U, V, and \V to open. When relay Sdoes open, therefore, relays U, V, and W are then all open, and itfollows that a relay which should. be open under these conditions willremain open, since the corresponding relay will then be supplied withcurrent having a magnitude which is not sufficient to pick up the relay.

Although I have herein shown and described only two forms of signalingapparatus embodying my invention, it is understood that various changesand modifications may be made therein within the scope of the ap pendedclaims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination, two relays selectively responsive to currents ofdiiferent magni-' tudes, a circuit for said relays including means forsupplylng said relays 1n series with current of one magnitude, means forat times interrupting said circuit and for supplying said relays with acurrent of different magnitude after the expiration of a time intervalwhich is sufficient to permit both relays to open, and indicatorscontrolled by said relays.

2. In combination, a first and a second relay, a slow-acting relaycontrolled by said first and second relays, a neutral relay and apolarized relay requiring currents of different magnitudes to energizethe relays, means controlled by said first and second relays and saidslow-acting relay for supplying said neutral and said polarized relaysin series with currents of different magnitudes and polarities toselectively operate said neutral and said polarized relays, andindicators selectively controlled by said neutral and polarized relays.

3. In combination, a first and a second normally energized relay, meansfor at times selectively de-energizing said relays, a slowacting relaycontrolled by front contacts of each of said first and second relays, aneutral l and a polarized relay, a first circuit I r said no tral andsaid polarized relays including front contacts of said first and secondrelays; a second circuit for said neutral and said polarized relaysincluding a front contact of said first relay, a back contact of s idsecond relay, and a back contact of said slow-acting relay; thirdcircuit for said neutral and said polarized relays including a backcontact of said first relay, a front contact of said second relay, and aback contact of said slow-acting relay, and indicators selectivelycontrolled by said neutral and said polarized relays.

a. In combination, a first and a second relay, a slow-acting relaycontrolled by said first and second relays, a neutral and a polarizedrelay located at a remote point and requiring currents of differentmagnitudes to energize the relays, means including a single pair of linewires and controlled by said first and second relays and saidslow-acting relay for supplying said neutral and said polarized relaysin series with currents of difierent magnitudes and polarities toselectively operate said neutral and said polarized relays, andindicators sel'jectively controlled by said neutral and said polarizedrelays.

5. In combination, a neutral relay and a polarized relay, twoindicators, means for energizing one or the other of said indicatorswhen said neutral relay is de-energized depending upon whether saidpolarized relay is energized in the normal or reverse direction, andmeans for energizing both of said indicators when said neutral andpolarized relays are both tie-energized.

6. In combination, a first and a second section of railway track, afirst track relay responsive to traffic conditions in said firstsection, a second track relay responsive to traffic conditions in saidsecond section, a slow-acting relay controlled by said first and secondrelays, a neutral and a polarized relay located at a remote point andrequiring currents of different magnitudes to energize the relays, meansincluding a single pair of line Wires and controlled by said first andsecond track relays and said slow-acting relay for supplying saidneutral and said polarized re lays in series Witlrcurrents of differentmagnltudes and polarities to selectlvely operate said neutral and saidpolarized relays, and indicators selectively controlled by said neutraland said polarized relays. In testimony whereof I affix my signature.

JAMES J VANHORN.

